JP2012020426A - Molding injection nozzle of hollow article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding injection nozzle of a hollow article, which can uniformize a wall surface in a hollow part and shorten a molding cycle by improving a structure of a part coming into contact with an injected molding material.SOLUTION: The molding injection nozzle 1 includes: a cylindrical discharge end 4a constituting a metal injector nozzle part 4 provided on the one end of a nozzle body 2; a nozzle end 7a inserted in the discharge end 4a by advancingly driving an injector piston 6 disposed so as to be movable forwadly and backwardly in the nozzle body 2; a high-pressure gas circulation hole 13 and a high-pressure water circulation hole 15 for pressure-feeding high-pressure gas and high-pressure water in the molding material 43 which is discharged in a cavity 42 from a protruding end through the inside of the discharge end 4a in a state that the nozzle end 7a is retracted from the discharge end 4a by the advance driving of the injector piston 6; and a low thermal conductivity chip 20 mounted to a distal end contacting with the molding material 43 of the nozzle end 7a.

Description

  The present invention relates to a molding injection nozzle for molding a hollow article by injecting a molding resin material, a gas or the like and a high-pressure fluid into a molding die.

  Conventionally, various means such as extrusion molding, pultrusion molding, gas blow molding, and water injection molding have been known as molding means for hollow articles such as synthetic resin pipes.

  Considering the molding means by water injection molding among the conventional molding means for hollow products, for example, a molding die is used, the molding material is filled in the cavity of the molding die, and further, the inside of the filled molding material The present situation is that there is no suitable injection nozzle for forming a hollow product by injecting high-pressure gas and high-pressure water into a hollow part.

  In the case of this type of conventional injection nozzle for molding, when a hollow part is formed by injecting high-pressure gas and high-pressure water into the molding material filled in the cavity of the molding die, The nozzle tip is made of metal, and a part of the injected molding material covers the nozzle tip, so the molding material is immediately cooled and solidifies over the nozzle tip, forming a hollow product. In some cases, it may be difficult to inject gas and water.

  In other words, in the case of a conventional injection nozzle for molding a hollow product, because the molding material is covered on the tip of the nozzle, gas or water leaks out of the cavity, or the roughness of the cavity wall surface is not uniform and becomes a rough surface. In other words, it was difficult to form a high-quality hollow article.

  In Patent Document 1 attached, the resin material in the passage from the nozzle receiving part of the mold to the cavity is kept in a molten state by a heater and the hot chip close to the gate communicating with the cavity is passed from the tip through the gate to the cavity. An injection molding apparatus has been proposed in which a gas blow-out portion for injecting an inert gas into a molten resin is provided to form a hollow article in a mold.

  In the case of this patent document 1, since it is the structure which arrange | positions the hot tip which incorporated the heater in the said channel | path other than the injection nozzle, it did not take the countermeasure against solidification of molten resin to the injection nozzle itself. The structure of the injection molding apparatus as a whole has been complicated.

JP-A-6-155524

  The problem to be solved by the present invention is that the structure of the nozzle in contact with the injected molding material is improved, and after filling the molding material, the gas and water are hollowed out while the solidification is suppressed. There is no injection nozzle for molding a hollow product with a simple configuration that can be involved in the formation of the part and can realize the homogenization of the wall surface of the hollow part and the shortening of the molding cycle.

  According to the present invention, a high-pressure fluid is pumped from a protruding end of a metal injector nozzle portion mounted on the mold into the molding material injected into the mold cavity, thereby forming a hollow product having a hollow inside. The most important feature of the injection nozzle for molding a hollow product is that a low thermal conductivity chip is attached to a portion of the injector nozzle portion that contacts the molding material in the protruding end region.

  According to the first aspect of the present invention, the high pressure fluid is pumped from the protruding end of the metal injector nozzle portion mounted on the mold into the molding material injected into the cavity of the mold, When molding a hollow product, the injection nozzle is in contact with the protruding end of the injector nozzle part because it has a structure with a low thermal conductivity chip attached to the protruding end region of the injector nozzle part. Cooling and solidification of the mold is suppressed by the low thermal conductivity chip, so that a high-pressure fluid can be pumped into the molding material without hindrance and the molding material can be inflated accurately. It is possible to realize and provide a hollow molding injection nozzle capable of achieving uniformity and shortening the molding cycle.

  According to the second aspect of the present invention, the high pressure fluid is pumped from the protruding end of the metal injector nozzle portion to be mounted on the mold into the molding material injected into the mold cavity, A hollow injection molding nozzle for forming a hollow hollow article, comprising a cylindrical discharge end part constituting an injector nozzle part provided at one end of the nozzle body, and a piston arranged so as to be able to advance and retreat in the nozzle body. A metallic nozzle end portion inserted into the discharge end portion by forward drive, and a state where the nozzle end portion is retracted from the discharge end portion by a backward drive of a piston, from the protruding end through the discharge end portion. A high-pressure fluid pumping path for pumping a high-pressure fluid into the molding material discharged into the cavity, and a low thermal conductivity chip attached to a tip portion contacting the molding material at the nozzle end. In addition, as in the first aspect of the invention, the cooling and solidification of the injected molding material is suppressed by the low thermal conductivity chip, so that a high-pressure fluid can be pumped into the molding material without hindrance and the interior of the molding material can be accurately obtained. It is possible to realize and provide a hollow product molding injection nozzle that can be inflated and can make the wall surface of the hollow portion uniform in the molded hollow product and shorten the molding cycle.

  According to the third aspect of the present invention, the high pressure fluid is pumped from the protruding end of the metal injector nozzle portion mounted on the mold into the molding material injected into the mold cavity, A hollow injection molding nozzle for forming a hollow hollow article, comprising a cylindrical discharge end part constituting an injector nozzle part provided at one end of the nozzle body, and a piston arranged so as to be able to advance and retreat in the nozzle body. A metallic nozzle end portion inserted into the discharge end portion by forward drive, and a state where the nozzle end portion is retracted from the discharge end portion by a backward drive of a piston, from the protruding end through the discharge end portion. A high-pressure fluid pumping path having a two-system structure for pumping high-pressure gas and high-pressure water into the molding material discharged into the cavity, and a resin material, wood or wood attached to the tip portion of the nozzle end contacting the molding material Based on a structure having a low thermal conductivity chip formed of a material selected from rubber, the cooling and solidification of the injected molding material is suppressed by the low thermal conductivity chip, as in the invention of claim 2, thereby The high-pressure fluid consisting of high-pressure gas and high-pressure water can be pumped into the molding material without any hindrance so that the molding material can be accurately inflated. A hollow injection molding nozzle that can be shortened can be realized and provided.

  According to the fourth aspect of the present invention, the high pressure gas and high pressure water are formed from the protruding end of the metal injector nozzle portion mounted on the mold with respect to the molding material injected into the mold cavity. A hollow injection molding nozzle that pumps a fluid and forms a hollow product with a hollow inside, a cylindrical discharge end part that constitutes an injector nozzle part provided at one end of the nozzle body, and a nozzle body A metal nozzle end inserted into the discharge end by a forward drive of a piston arranged to be able to advance and retreat, and the discharge end in a state where the nozzle end is retracted from the discharge end by a backward drive of the piston. A high-pressure gas pumping path for pumping high-pressure gas into the molding material discharged into the cavity from the projecting end through the inside of the part, and a high pressure pumping high-pressure water into the molding material discharged into the cavity. The base of the structure which has a water pressure feeding path | route, and the low thermal conductivity chip | tip formed with the material chosen from the resin material, wood, or rubber | gum attached to the front-end | tip part which contacts the molding material of the said nozzle edge part. As in the case of the present invention, the cooling and solidification of the injected molding material is suppressed by the low thermal conductivity chip. It is possible to realize and provide an injection nozzle for forming a hollow product that can be accurately inflated and can make the wall surface of the hollow portion uniform in the formed hollow product and shorten the molding cycle.

FIG. 1 is a schematic configuration diagram showing a perspective view of the entire structure of an injection nozzle for forming a hollow article according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram showing a perspective view of the structure of a state in which the nozzle end driven by the piston is moved toward the discharge end in the injection nozzle for forming a hollow article according to the present embodiment. FIG. 3 is a schematic configuration diagram showing a perspective view of the structure of a state in which the end of the nozzle driven by the piston is moved to the discharge end in the hollow injection molding nozzle according to the present embodiment and is placed in the molding material. is there. FIG. 4 is a schematic configuration diagram showing a perspective view of the structure of a state in which the nozzle end portion driven by the piston is retracted from the discharge end side in the injection nozzle for forming a hollow article according to the present embodiment. FIG. 5 is a perspective view of the structure of the injection nozzle for forming a hollow article according to the present embodiment in a state where the nozzle end driven by the piston is retracted from the discharge end side and high pressure gas and high pressure water are pumped to the molding material. FIG. FIG. 6 is an explanatory view showing a state in which the molding material is not solidified by the low thermal conductivity chip attached to the end of the nozzle in the hollow injection molding nozzle according to the present embodiment. FIG. 7 is an explanatory view showing a solidified state of the molding material when the low thermal conductivity chip is not attached to the nozzle end.

  According to the present invention, a high-pressure fluid is pumped from a protruding end of a metal injector nozzle portion mounted on the mold into the molding material injected into the mold cavity, thereby forming a hollow product having a hollow inside. An injection nozzle for forming a hollow product, wherein the discharge end is formed by a cylindrical discharge end portion constituting an injector nozzle portion provided at one end of the nozzle body, and a forward drive of a piston disposed in the nozzle body so as to be movable back and forth. The metal nozzle end inserted into the part and the nozzle end withdrawn from the projecting end into the cavity through the discharge end while the nozzle end is retracted from the discharge end by retreating the piston. Selected from a two-system high-pressure fluid pumping path that pumps high-pressure gas and high-pressure water into the molding material, and a resin material, wood, or rubber attached to the tip of the nozzle that contacts the molding material. It was realized by the configuration having a low thermal conductivity chip formed by charge.

Hereinafter, a hollow product injection nozzle according to an embodiment of the present invention will be described in detail with reference to FIGS.
As shown in FIG. 1, the injection nozzle 1 for molding a hollow product 51 according to the present embodiment has, for example, a substantially cylindrical nozzle body 2 as a whole.

  The nozzle body 2 includes, for example, a cylindrical rod cover body 3 and a head cover body 21 attached to the other end side of the rod cover body 3. An injector nozzle portion 4 for injecting gas or high-pressure water is disposed.

  The rod cover body 3 is a hollow cylinder located on the other end side, and houses a cylinder part 5 that houses an internal injector piston 6 so as to reciprocate in the directions of arrows a and b shown in FIG. A rod hole 5a is provided so as to communicate with the central portion in the longitudinal direction of the rod cover body 3 and through which the injector piston rod 7 integral with the injector piston 6 is inserted.

The injector nozzle portion 4 has a cylindrical discharge end portion 4a for injecting high-pressure gas or high-pressure water toward the cavity 42 of the hollow product molding die 41 schematically shown in FIG. It protrudes outward from the end face on the side.
Further, the injector nozzle portion 4 expands the valve seat 7b side to be brought into contact with a tapered valve seat 7b provided on the injector piston rod 7 from one end side of the rod cover body 3 inward. The concave receiving surface 4b is provided.

  Further, a nozzle end 7a that is integral with the injector piston rod 7 and has an outer diameter smaller than that of the injector piston rod 7 itself is inserted into and removed from the discharge end 4a of the injector nozzle portion 4. It is composed.

  As described above, the valve seat 7b is formed on the one end side of the injector piston rod 7 itself at a position that becomes the base end of the nozzle end portion 7a, and the valve seat 7b is formed on the receiving surface 4b as shown in FIG. The nozzle end 7a is sealed in the discharge end 4a ahead of the valve seat 7b.

  The head cover body 21 closes the other end of the rod cover body 3 and applies a preset pressure to the piston surface of the injector piston 6 on the rod cover body 3 side from the outer periphery to the inside. An A port 22 for injecting (liquid or gas) is provided, and a supply hose connected to a fluid supply source 31 (hydraulic pump, air compressor, etc.) is connected to the A port 22.

  The rod cover body 3 is for injecting a fluid (liquid or gas) for applying a preset pressure to the piston surface of the injector piston 6 on the side of the injector piston rod 7 through the inside from the outer periphery thereof. A port 11 is provided, and a supply hose connected to the fluid supply source 31 is connected to the B port 11.

  Further, the rod cover body 3 includes a C port 12 and a D port 14 on the outer peripheral portion thereof.

  The C port 12 is connected to a high-pressure gas supply source 32 via a gas pipe, passes through a gas flow hole 13 provided in the rod cover body 3, passes through the nozzle end 7a, and is preset in the discharge end 4a. A high-pressure gas (for example, an inert gas) at the above pressure is supplied.

The D port 14 is connected to a high-pressure water supply source 33 via a water hose, passes through a water flow hole 15 provided in the rod cover body 3, passes around the nozzle end portion 7 a, and enters the discharge end portion 4 a. Is configured to supply high-pressure water having a preset pressure.
Further, the gas and high-pressure water in the hollow portion of the molding material 43 pass through the water circulation hole 15 from the discharge end portion 4a through the nozzle end portion 7a, and are further discharged from the D port 14 to a tank (not shown). It is configured to collect.

  For example, a low thermal conductivity chip 20 having an annular shape that does not block the hole of the nozzle end 7a is attached to the protruding end of the nozzle end 7a.

  Examples of the material of the low thermal conductivity chip 20 include resin material, wood, rubber, and the like.

  Next, the molding operation of the hollow article 51 by the molding injection nozzle 1 according to the present embodiment will be described in detail with reference to FIGS.

  In the injection nozzle 1 for molding according to the present embodiment, first, as shown in FIGS. 1 and 2, a driving fluid is pressure-fed from the fluid supply source 31 to the cylinder portion 5 via the A port 22, and the injector piston. 6 and the injector piston rod 7 are advanced in the direction of arrow a, the nozzle end 7a is advanced into the discharge end 4a, and the low thermal conductivity tip 20 is projected forward from the end face of the discharge end 4a. The valve seat 7b is brought into contact with the receiving surface 4b on the back side of the discharge end 4a. This state is shown in FIG.

  Further, the nozzle end portion 7 a is made to face the molding material 43 injected in advance in the cavity 42 of the hollow product molding die 41. This state is schematically shown in FIG.

  Next, unlike the case described above, the fluid for driving is pumped from the fluid supply source 31 to the cylinder portion 5 through the B port 22, and the injector piston 6 and the injector piston rod 7 are moved backward in the direction of arrow b. Thus, the nozzle end portion 7a is retracted rearward from the receiving surface 4b on the back side of the discharge end portion 4a. That is, the inside of the discharge end 4a is in a hollow state. This state is schematically shown in FIG.

Next, immediately after the nozzle end portion 7a reaches the position shown in FIG. 4, the molding material in the cavity 42 passes from the high-pressure gas supply source 32 through the C port 12, the gas flow hole 13, and the discharge end portion 4a. High pressure gas is fed into the inside of the molding material 43 in the cavity 42 through the D port 14, the water circulation hole 15, and the inside of the discharge end 4 a from the high pressure water supply source 33. A hollow product molding process is performed by inflating the molding material 43 in the cavity 42 from the inside like a balloon. This state is schematically shown in FIG.
Then, after the hollow product molding process is carried out and the pressure holding and cooling processes are completed, the gas and high-pressure water in the hollow portion of the molding material 43 are allowed to pass through the water circulation hole 15 from the discharge end portion 4a through the nozzle end portion 7a. , Discharged from the D port 14 and collected in a tank (not shown).

  Thereafter, the nozzle body 2 is removed from the hollow product molding die 41, and after cooling the molded product in the cavity 42, the molded product is taken out from the hollow product molding die 41, as shown in FIG. A hollow product 51 having a hollow portion inside is obtained.

The stage where the nozzle end portion 7a as shown in FIG. 3 described above is placed in the molding material 43 in the cavity 42 of the hollow mold 41 will be described in more detail.

  As shown in FIG. 6, since the low thermal conductivity chip 20 attached to the nozzle end 7a protrudes forward from the end face of the discharge end 4a, the low thermal conductivity chip 20 has a low thermal conductivity. Due to the action, cooling and solidification of the injected molding material 43 that comes into contact with the protruding end portion of the nozzle end portion 7a is suppressed and it is difficult to solidify. As a result, it is possible to make the wall surface of the hollow part uniform in the molded hollow article 51 and shorten the molding cycle.

  On the other hand, when the low thermal conductivity chip 20 is not mounted on the nozzle end 7a, the molding material 43 is injected into the cavity 42 of the hollow mold 41 from the metal nozzle end 7a. Immediately after the cooling and solidification of the molding material 43 proceeds, as shown in FIG. 7 as a comparative example, a skin layer portion 43a (cooling of the molding material) like a bamboo node is formed in the protruding end region of the nozzle end portion 7a. A portion where the viscosity of the molten resin is increased due to progress of solidification is generated, which hinders the injection process of high-pressure gas and high-pressure water in the next process, resulting in quality deterioration of the molded product.

  As described above, according to the injection nozzle 1 for molding the hollow article 51 according to the present embodiment, the molding material 43 that comes into contact with the nozzle end 7a by adding a very simple element such as mounting the low thermal conductivity chip 20 on the nozzle end 7a. Can be prevented from solidifying, the formation of the skin layer 43a can be prevented, and high-pressure gas and high-pressure water can be easily injected into the molding material 43. Improvement and shortening of the molding cycle by using only the single molding injection nozzle 1 can be realized.

  In addition to the case described above, it is of course possible to embed an electric heater in the nozzle end portion 7a to prevent the molding material from solidifying and to suppress solidification.

  The injection nozzle for molding according to the present invention is an injection nozzle type for forming various hollow products having a hollow portion such as a round tube material, a square tube material, a box shape material, a joinery material made of a resin material, or a member similar thereto. The present invention can be widely applied as a molding injection nozzle combined with a molding die to be performed.

DESCRIPTION OF SYMBOLS 1 Molding injection nozzle 2 Nozzle main body 3 Rod cover body 4 Injector nozzle part 4a Discharge end part 4b Receiving surface 5 Injector cylinder part 5a Rod hole 6 Injector piston 7 Injector piston rod 7a Nozzle end part 7b Valve seat 11 B port 12 C port 13 High Pressure Gas Flow Hole 14 D Port 15 High Pressure Water Flow Hole 20 Low Thermal Conductivity Chip 21 Head Cover Body 22 A Port 31 Fluid Supply Source 32 High Pressure Gas Supply Source 33 High Pressure Water Supply Source 41 Hollow Product Mold 42 Cavity 43 Molding Material 43a Skin layer 51 Hollow product

Claims (4)

A hollow product in which a high-pressure fluid is pumped from a protruding end of a metal injector nozzle portion mounted on the mold into the molding material injected into the cavity of the mold to form a hollow product with a hollow inside. An injection nozzle for molding,
An injection nozzle for molding a hollow product, wherein a low thermal conductivity chip is attached to a portion of the injector nozzle portion that contacts the molding material in the protruding end region. A hollow product in which a high-pressure fluid is pumped from a protruding end of a metal injector nozzle portion mounted on the mold into the molding material injected into the cavity of the mold to form a hollow product with a hollow inside. An injection nozzle for molding,
A cylindrical discharge end part constituting an injector nozzle part provided at one end of the nozzle body;
A metal nozzle end that is inserted into the discharge end by a forward drive of a piston that is movably disposed in the nozzle body;
High-pressure fluid pumping that pumps high-pressure fluid into the molding material injected into the cavity from the protruding end through the discharge end in a state where the nozzle end is retracted from the discharge end by driving the piston backward. Route,
A low thermal conductivity chip attached to the tip portion in contact with the molding material of the nozzle end,
An injection nozzle for molding a hollow article, characterized by comprising: A hollow product in which a high-pressure fluid is pumped from a protruding end of a metal injector nozzle portion mounted on the mold into the molding material injected into the cavity of the mold to form a hollow product with a hollow inside. An injection nozzle for molding,
A cylindrical discharge end part constituting an injector nozzle part provided at one end of the nozzle body;
A metal nozzle end portion inserted into the discharge end portion by a forward drive of a piston disposed in the nozzle body so as to be movable back and forth;
High pressure gas and high pressure water are pumped into the molding material discharged from the protruding end into the cavity through the discharge end in a state where the nozzle end is retracted from the discharge end by the backward drive of the piston. A high-pressure fluid pumping path with a two-line structure;
A low thermal conductivity chip formed of a material selected from a resin material, wood, or rubber attached to the tip portion in contact with the molding material of the nozzle end;
An injection nozzle for molding a hollow article, characterized by comprising: A high-pressure fluid consisting of high-pressure gas and high-pressure water is pumped from the protruding end of a metal injector nozzle part mounted on the mold into the molding material injected into the mold cavity, and the interior is hollow. An injection nozzle for molding a hollow product for molding a product,
A cylindrical discharge end part constituting an injector nozzle part provided at one end of the nozzle body;
A metal nozzle end portion inserted into the discharge end portion by a forward drive of a piston disposed in the nozzle body so as to be movable back and forth;
High pressure gas pumping that pumps high pressure gas into the molding material discharged from the projecting end into the cavity through the discharge end while the nozzle end is retracted from the discharge end by driving the piston backward. A high-pressure water pumping path for pumping high-pressure water into the path and the molding material discharged into the cavity;
A low thermal conductivity chip formed of a material selected from a resin material, wood, or rubber attached to the tip portion in contact with the molding material of the nozzle end;
An injection nozzle for molding a hollow article, characterized by comprising:

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